April 22, 2008

Hello friends i am writing post after a long time but now in the future i wrote continuously, here in this post i am going to share some interesting point about network security.

For the few years ago no body is worried about the network security because at that time computer networks are primarily used by university researchers for sending e-mail and by corporate employees for sharing printers but now a day network security is an important factor for any computer network. Generally network security is concerned with people trying to access remote services that they are not authorized to use.

Network Security problem can be roughly divided into four closely intertwined areas: secrecy, authentication, non repudiation and integrity control. All these issues occur in traditional systems, too, but with some significant differences. Now we came to our main issue of network security, first of all we had to understand that where the network security belongs in the protocol stack. The answer is there is probably no one single place that means every network layer has something to contribute. In the case of data link layer, packets on a point to point line can be encrypted as they leave one machine and decrypted as they enter another. This solution also breaks down when packets have to traverse multiple routers because at each router the message is decrypted.

In the case of network layer, firewalls can be installed to keep good packets and bad packets out. In the transport layer, entire connections can be encrypted, end to end, that is process to process. As we discussed issues authentication and non-repudiation can only be handled in application layer. From all the above points it is clear that network security is dependent on each layer of network and it can be concluded that no computer network is 100% secure.